Snakebots would assist with rescues, bomb searches

A team of researchers at the Georgia Institute of Technology is studying closely how snakes move and slither. Their scaly goal is to create robots capable of gliding into tight spaces and rough terrain to perform tasks such as searching for survivors in collapsed buildings or checking for roadside bombs.

The team, which consists of graduate students and scientists, has developed two robots so far. Known as Scalybot 1 and Scalybot 2, the proof-of-concept machines mimic how snakes move on different surfaces.

Scientists have long been interested in snakes for robot designs, said David Hu, assistant professor of mechanical engineering and the project’s lead. But while many of these earlier designs are very sophisticated, they were not very efficient because they relied on wheels or non-moving gripping surfaces when interacting with the ground.

Instead, Hu, who has a secondary specialty in biology, studied snake’s scales — the part that directly interfaces with the ground. Both of the test robots have a surface made up of small metal scales arranged like shingles. As the machine moves, each scale alters its angle of attack to provide traction.

The most recent robot, Scalybot 2 replicates how snakes move up steep slopes and on different types of terrain. Known as rectilinear locomotion, it allows snakes to lift their ventral, or belly, scales and pull themselves forward by undulating their muscles from head to tail. Hu’s partner on the project, Hamid Marvi, a mechanical engineering doctoral candidate at Georgia Tech, studied how the scales in snakes' skin shift to provide traction.

This type of motion also allows snakes to travel more efficiently by letting them lift and extend their scales. Rectilinear motion is very useful for robots moving through pipes or narrow crevices, for maintenance or search and rescue missions.

Scalybot 1 replicated concertina locomotion, the contracting and expanding motion of muscles and scales, that allows snakes to climb vertical objects, such as trees, and provide basic ground locomotion.

The Georgia Tech team is now beginning work on the third type of snake locomotion — sidewinding. This type of locomotion is mostly used by snakes to cross sand and other loose terrain. To better understand this technique, Hu’s team will be studying rattlesnakes.

When all the different types of snake locomotion are studied, and how their respective scale/ground interactions are worked out, Hu hopes that these techniques will allow researchers to develop more efficient and capable snakebots.